Three other men were killed in what a senior Obama administration official described as "a surgical raid by a small team designed to minimise collateral damage".

These were believed to be two al-Qaeda couriers who lived at the compound, along with their families, and an adult son of bin Laden. A woman being used as a shield by one of the al-Qaeda men during the firefight was also killed and two other women wounded.

A helicopter involved in the raid suffered mechanical failure and was blown up by the American team, none of whom were killed or injured. The Pakistani government was not informed of the raid until after it was over.

Details of the make-up of the team that killed bin Laden were closely guarded but the CIA was closely involved in the planning and execution of the raid.

Troops from a SEAL unit - the US Navy's elite Special Forces cadre that draws its name from Sea, Air, Land, is understood to have formed its core.

The compound, in Abbotabad, some 35 miles from Islamabad, was built in 2005 and appears to have been the bin Laden family residence for some time.

It took years for the compound to be located. Initially, the CIA knew only the nom de guerre of a man believed to be a trusted courier for bin Laden. Four years ago, his true identity was discovered and two years ago the places in Pakistan where he frequented were established.

The crucial breakthrough came last August when the compound where the courier lived along with his brother, another courier, was pinpointed and President Barack Obama briefed. The compound was in an affluent area of Abbotabad where many retired Pakistani military officers lived.

Initially built in a secluded area at the end of a dirt road, more homes had sprung up nearby. But the compound was about eight times larger than any other residence. It was protected by two security gates and 12-18ft high walls.

The main three-storey building in the compound had a terrace hidden from view by a 7ft wall and many areas were sealed off by internal walls.

Although the value of the compound was assessed at $1 million, the two couriers had no known source of income and there was no telephone or internet service.

Unlike their neighbours, occupants of the compound burned all their rubbish.

American intelligence agencies involved in assessing the compound included the CIA, the National Security Agency and the National Geospatial Agency.

Eventually, it was concluded that a third family lived in the compound - the bin Laden family, including the al-Qaeda leader and his youngest wife.

A drone strike on the compound was considered but ruled out because of the danger of killed large numbers of Pakistani civilians.

Instead, Mr Obama gave his authorisation last Friday for a highly risky helicopter assault that eventually took place in the early hours of Sunday morning Pakistan time.